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Plenum Spacer For 250Gt

fatboyslim27
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scotty nm35 Grand Master

scotty nm35

Posted
Posted

Not sure, but why would you bother?

Best thing to do is rip off all the plenum parts, and the lower runners, and clean the whole lot thoroughly as there will be a LOT of built up carbon down the runners. You will need to make a scraper to clean the head ports out. Doing this will give you all your top end back. You will go through a lot of carb cleaner so buy a box... You might want some oven cleaner/gasket stripper to help remove the built up gunk.

Deleting the vac operated swirl valve before the head might increase power a little at the expense of a little cruise economy.

Deleting EGR would help keep the lot clean so you don't have to do all this work again, again at the expense of cruise economy.

fatboyslim27 Rookie

fatboyslim27

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Main reason is just to squeeze a bit more power out of the engine. I know i should have gone for the 350GT if i wanted power but can't argue with the price i got my 250 for. Already have a z tube and a K&N drop in. Will try giving the inside of the plenum a clean, but any idea if the 350GT spacers would work?

scotty nm35 Grand Master

scotty nm35

Posted
Posted

They don't give power gains from my experience, and modding the engine without first maintaining it properly is a little backwards imo. You will gain more power changing to a synthetic oil than the spacer can ever give.

Stick the stock air panel back in firstly, or at least a cotton element as you have already taken a backwards step. You might want to clean your AFM element too, now you have most probably sprayed a fine mist of K+N oil onto the hotwire...

Ztube does absolutely nothing, other than make the intake louder. It is just a bit of pipe, were you expecting gains from it?

fatboyslim27 Rookie

fatboyslim27

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Done. Replaced with a standard one from Ryco. Got some new oil for it as well, full synthetic. The current oil is looking pretty minging.

No not at all, and if there were any they'd be so minimal i wouldn't feel it. A lot of other people have reported close to 5-8% gains with a spacer, so i was just curious.

sonicii Veteran

sonicii

Posted
Posted

Some have done dyno runs to show the benefits of the space on the 3.5L engine, so there are some gains there, not sure if that would translate into any gains on the 2.5L DD engine though.

the Z tube is absolutely just for sounds though.. after all the 350Z produces the same power/torque as the 3.5L engine in the V35.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Here is the direct injection intake assembly that creates swirl in the chamber, it essentially shuts off one intake valve at high vacuum. (idle/cruise) You can see how cleaning or preferably removal of this assembly would benefit power production. It's the first thing I would be doing if I had a dd in service. Followed by a turbo. :P

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post-63525-0-67603000-1390309115_thumb.jpg

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